An operation check before official operation needs to be performed in a web application system in which a web server performs various processing in response to user's operation made for a web browser on his or her client machine. Conventionally, the operation check has been performed by preparing a large number of test clients and corresponding large number of test users and by having the test users operate the web browsers on the test clients in the same manner as official operation time.
Further, a client simulation program has been used for the operation check. The client simulation program has the test users operate the web browsers on the test clients in the same manner as official operation time and traces data transmitted and received between the client and web server to acquire trace data and, afterward, repeats operation according to the trace data.
As a prior art relating to the present invention, there is known Patent Document 1 described below. A session management method in a web application disclosed in Patent Document 1 repeats transmission/reception of request data at given intervals independently of user's operation on the client machine to thereby confirm an existence of a connection called “session”.    Patent Document 1: Jpn. Pat. Appln. Laid-Open Publication No. 2003-233585 (pages 4 to 5, FIG. 1)